How to tell if gcc uses GNU or Sun linker on Solaris?

[Dr. David Kirkby]

Dennis Clarke wrote:
>> Is there any way to tell for certain if gcc uses the GNU or Sun linker
>> on Solaris, in a program? I would also like to do the same for the
>> assembler, though that is less important to me.
>>
>> I can tell on my machine it uses the Sun linker and assembler
>>
>> $ gcc -v
>> Using built-in specs.
>> Target: sparc-sun-solaris2.10
>> Configured with: ../gcc-4.4.1/configure
>> --prefix=/usr/local/gcc-4.4.1-sun-linker/ --with-as=/usr/ccs/bin/as
>> --without-gnu-as --with-ld=/usr/ccs/bin/ld --without-gnu-ld
>> --enable-languages=c,c++,fortran --with-mpfr-include=/usr/local/include
>> --with-mpfr-lib=/usr/local/lib --with-gmp-include=/usr/local/include
>> --with-gmp-lib=/usr/local/lib CC=/usr/sfw/bin/gcc CXX=/usr/sfw/bin/g++
>> LDFLAGS='-R /usr/local/lib -L /usr/local/lib'
>> Thread model: posix
>> gcc version 4.4.1 (GCC)
>>
>>
>> Looking there I see '--without-gnu-as' and '--without-gnu-ld', but there
>> is no guarantee someone uses those options when configure gcc. Here it
>> is even more clear, with -with-ld=/usr/ccs/bin/ld and
>> --with-as=/usr/ccs/bin/as. But what happens if I don't specify any of
>> this when I build gcc? Would it just find the first linker and assembler
>> in the path? In which case, how could I now determine what it uses?
> 
> Run gcc -v foo.c
> 
> $ gcc -v -o hello hello.c
> Using built-in specs.
> Target: i386-pc-solaris2.10
> Configured with: /export/medusa/dclarke/build/GCC/gcc-4.3.4/configure
> --build=i386-pc-solaris2.10 --with-gnu-as --with-as=/opt/csw/bin/gas
> --without-gnu-ld --with-ld=/usr/ccs/bin/ld --with-cpu-32=i386
> --with-cpu-64=opteron --with-arch-32=i386 --with-arch-64=opteron
> --enable-stage1-languages=c --enable-nls --with-libiconv-prefix=/opt/csw
> --enable-threads=posix --prefix=/opt/csw/gcc4 --with-local-prefix=/opt/csw
> --enable-shared --enable-multilib --with-included-gettext
> --with-system-zlib --with-gmp=/opt/csw --with-mpfr=/opt/csw
> --enable-languages=c,c++,objc,fortran --enable-bootstrap
> Thread model: posix
> gcc version 4.3.4 (GCC)
> COLLECT_GCC_OPTIONS='-v' '-o' 'hello' '-mtune=generic'
>  /opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/cc1 -quiet -v hello.c
> -quiet -dumpbase hello.c -mtune=generic -auxbase hello -version -o
> /var/tmp//ccTig2Nt.s
> ignoring nonexistent directory
> "/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/../../../../i386-pc-solaris2.10/include"
> #include "..." search starts here:
> #include <...> search starts here:
>  /opt/csw/include
>  /opt/csw/gcc4/include
>  /opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/include
>  /opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/include-fixed
>  /usr/include
> End of search list.
> GNU C (GCC) version 4.3.4 (i386-pc-solaris2.10)
>         compiled by GNU C version 4.3.4, GMP version 4.3.1, MPFR version
> 2.4.2-rc1.
> GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
> Compiler executable checksum: 9ba7f205b9cefa6eae48c8f511c89b44
> COLLECT_GCC_OPTIONS='-v' '-o' 'hello' '-mtune=generic'
>  /opt/csw/bin/gas -v -V -Qy -s -o /var/tmp//ccClhznU.o /var/tmp//ccTig2Nt.s
> GNU assembler version 2.19.1 (i386-pc-solaris2.8) using BFD version (GNU
> Binutils) 2.19.1
> COMPILER_PATH=/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/:/usr/ccs/bin/
> LIBRARY_PATH=/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/:/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/../../../:/lib/:/usr/lib/
> COLLECT_GCC_OPTIONS='-v' '-o' 'hello' '-mtune=generic'
>  /opt/csw/gcc4/libexec/gcc/i386-pc-solaris2.10/4.3.4/collect2 -V -Y
> P,/usr/ccs/lib:/usr/lib -Qy -o hello /usr/lib/crt1.o /usr/lib/crti.o
> /usr/lib/values-Xa.o
> /opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/crtbegin.o
> -L/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4
> -L/opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/../../..
> /var/tmp//ccClhznU.o -lgcc -lgcc_eh -lc -lgcc -lgcc_eh
> /opt/csw/gcc4/lib/gcc/i386-pc-solaris2.10/4.3.4/crtend.o /usr/lib/crtn.o
> ld: Software Generation Utilities - Solaris Link Editors: 5.10-1.496
> $
> 
> If you look closely you see :
> 
> GNU assembler version 2.19.1 (i386-pc-solaris2.8) using BFD version (GNU
> Binutils) 2.19.1
> 
> and then
> 
> ld: Software Generation Utilities - Solaris Link Editors: 5.10-1.496
> 
> $ file hello
> hello: ELF 32-bit LSB executable 80386 Version 1, dynamically linked, not
> stripped, no debugging information available
> 
> $ /usr/ccs/bin/mcs -p hello
> hello:
> 
> @(#)SunOS 5.10 Generic January 2005
> 
> @(#)SunOS 5.10 Generic January 2005
> 
> @(#)SunOS 5.10 Generic January 2005
> 
> GCC: (GNU) 4.3.4
> 
> GCC: (GNU) 4.3.4
> 
> GCC: (GNU) 4.3.4
> 
> @(#)SunOS 5.10 Generic January 2005
> ld: Software Generation Utilities - Solaris Link Editors: 5.10-1.496
> 
> 
> 

I can see in this case you can tell, but it's hardly a reliable way is 
it. Who knows exactly what the output will be. I don't see any guarantee 
this could be used reliably in a test.

I must admit, I can't ever actually recall seeing a gcc where the 
building has not put --with-gnu-ld or --without-gnu-ld, or specified 
something on the configure options to give it away. But I suspect 
someone has built a gcc without doing that.

I think in some open solaris distributions, the gnu assembler is used, 
but the sun linker. So even finding binutils in an output somewhere does 
not really help.